php多维数组合并相同key怎么实现

可以使用array_merge_recursive()函数来合并多维数组中相同的键。

示例代码如下：

$array1 = array(
    "color" => array("favorite" => "red"),
    "food" => array("fruit" => "apple", "vegetable" => "carrot")
);

$array2 = array(
    "color" => array("favorite" => "blue"),
    "food" => array("fruit" => "banana")
);

$result = array_merge_recursive($array1, $array2);

print_r($result);

输出结果为：

Array
(
    [color] => Array
        (
            [favorite] => Array
                (
                    [0] => red
                    [1] => blue
                )

        )

    [food] => Array
        (
            [fruit] => Array
                (
                    [0] => apple
                    [1] => banana
                )

            [vegetable] => carrot
        )

)

在合并过程中，相同的键会被合并为一个数组，然后是其他键值对的合并。